fix(sf): enforceMemoryCap sweeps orphaned embeddings too

Same orphan-cleanup as 1b71ddd17 but for the batch path. enforceMemoryCap
calls supersedeLowestRankedMemories, which marks N lowest memories
superseded in one UPDATE — bypassing the per-memory supersede embedding
cleanup. The result was that capping a project at 50 memories left dead
embedding rows for everything that got demoted.

Now: a single DELETE-IN-SUBQUERY removes embedding rows for any memory
that no longer has superseded_by IS NULL — covers both the cap path
and any historical orphans from before the per-row cleanup landed.
Best-effort; cap enforcement is load-bearing, embedding cleanup is not.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/resources/extensions/sf/memory-store.ts

@@ -434,6 +434,12 @@ export function decayStaleMemories(thresholdUnits = 20): void {
 
 /**
  * Supersede lowest-ranked memories when count exceeds cap.
+ *
+ * After superseding, sweeps memory_embeddings for rows whose memory is now
+ * superseded — keeps the embeddings table aligned with active memories so
+ * loadAllEmbeddings doesn't carry dead vectors and storage doesn't grow
+ * unbounded. Best-effort cleanup; the cap enforcement is the load-bearing
+ * step.
  */
 export function enforceMemoryCap(max = 50): void {
 	if (!isDbAvailable()) return;
@@ -451,6 +457,21 @@ export function enforceMemoryCap(max = 50): void {
 
 		const excess = count - max;
 		supersedeLowestRankedMemories(excess, new Date().toISOString());
+
+		// Sweep orphaned embeddings for newly-superseded memories.
+		try {
+			adapter
+				.prepare(
+					`DELETE FROM memory_embeddings WHERE memory_id IN (
+            SELECT id FROM memories WHERE superseded_by IS NOT NULL
+          )`,
+				)
+				.run();
+		} catch {
+			// Orphaned rows are harmless to queries (loadAllEmbeddings filters
+			// by superseded_by IS NULL); skip-on-error keeps cap enforcement
+			// load-bearing without coupling to embedding cleanup.
+		}
 	} catch {
 		// non-fatal
 	}